LOUD buzzing on LFE input
Erik Tracy
Posts: 4,673
Well - sounds like I got a bad LFE input on my sub.
I run two sets of sub cables - one from my AVR sub out to the LFE input, and another set from the pre-outs on my Int Amp for 2channel listening.
If I want to listen to music, I hook up the line level inputs and disconnect the LFE cable.
If I want to watch movies I disconnect the line level cables and hook up the LFE cable.
Well, today, I go to hook up the LFE input, turn on the sub and BUZZZZZZ.
WTF?
I turn off the sub, disconnect the LFE cable, hook up line level cables, all is fine, sub works normal with CDs, LPs.
Disconnect everything from the sub, turn it on...no buzzing.
I rechecked the LFE cable - yup - the HT gremlins did not switch outputs on my during the night.
I thought maybe I have a new ground loop problem of some sort, so I disconnected the AVR end of the LFE cable, just had the LFE end hooked up at the sub...and...BUUUZZZZZZZZ.
Its as if the LFE input jack has shorted.
Email sent to Chad at Epik - will have to see what he says.
I run two sets of sub cables - one from my AVR sub out to the LFE input, and another set from the pre-outs on my Int Amp for 2channel listening.
If I want to listen to music, I hook up the line level inputs and disconnect the LFE cable.
If I want to watch movies I disconnect the line level cables and hook up the LFE cable.
Well, today, I go to hook up the LFE input, turn on the sub and BUZZZZZZ.
WTF?
I turn off the sub, disconnect the LFE cable, hook up line level cables, all is fine, sub works normal with CDs, LPs.
Disconnect everything from the sub, turn it on...no buzzing.
I rechecked the LFE cable - yup - the HT gremlins did not switch outputs on my during the night.
I thought maybe I have a new ground loop problem of some sort, so I disconnected the AVR end of the LFE cable, just had the LFE end hooked up at the sub...and...BUUUZZZZZZZZ.
Its as if the LFE input jack has shorted.
Email sent to Chad at Epik - will have to see what he says.
H9: If you don't trust what you are hearing, then maybe you need to be less invested in a hobby which all the pleasure comes from listening to music.
Post edited by Erik Tracy on
Comments
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I got out my multi-meter and did some checking.
I disconnected power from the sub, hooked up an RCA cable to the line level input and measured the other end - got a reading of 55.4 k-ohms for both the Left and Right line level inputs.
I moved the cable to the LFE input - expecting to get a short reading at the multimeter, but I got a reading of 60.1k-ohms.
So the LFE jack does not seem shorted.
H9: If you don't trust what you are hearing, then maybe you need to be less invested in a hobby which all the pleasure comes from listening to music. -
I was sitting quietly one day a while back in the man cave when one of my sub's began buzzing VERY LOUD, I ran over to unplug it.The system was off at the time.I tried another line level cable and no buzz.Tried the original cable..BUZZ!!!!!This is with the system off,sub plugged in to power,that's all.So my problem was a bad cable.
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I was sitting quietly one day a while back in the man cave when one of my sub's began buzzing VERY LOUD, I ran over to unplug it.The system was off at the time.I tried another line level cable and no buzz.Tried the original cable..BUZZ!!!!!This is with the system off,sub plugged in to power,that's all.So my problem was a bad cable.
Yeah - that's what I was thinking too, so I got by box of goodies out and hooked up a plain old fashioned RCA cable and hooked up one end to the sub and measured the impedance at the other end.
And I got an "open" reading on the multimeter...ie no circuit reading and not a short.
WTF?
I moved the cable connections to the Line Level jack and got a reading of 55.4 k-ohms on both the left and right line level jacks.
Move it back to the LFE jack and nothing - open circuit.
So I started to twist and wiggle the RCA end at the LFE jack and watched the multimeter and it went all over the place but if I hold the cable at a certain angle at the sub jack, then the multimeter 'settles' to 60.1 K-ohms.
I tried a different cable - same thing.
I think I have a bad LFE jack on the sub - cold solder joint, solder joint that has cracked and is intermittent?
H9: If you don't trust what you are hearing, then maybe you need to be less invested in a hobby which all the pleasure comes from listening to music. -
Yup - verified it.
If I plug the cable in and twist it until I get the 60.1k-ohm reading to 'settle', then plug power to the sub and turn it on - I don't get the buzzing.
But - there is no way to guarantee that the connection with source going thru it would remain stable - it could go intermittent at any time and start buzzing.
H9: If you don't trust what you are hearing, then maybe you need to be less invested in a hobby which all the pleasure comes from listening to music. -
So I contacted Chad at Epik - he was ok with me removing the amp from the back of the cabinet and have a look-see at the LFE jack.
Problem is, I removed all of the perimeter screws around the amp to try and remove the amp and the amp doesn't want to come off.
Has anyone here with an Epik sub removed the amp from the back of the cabinet? Is there some sort of adhesive used to hold it in place?
I was thinking of using a screw driver to pry it off the back.
Thanks,
Erik
H9: If you don't trust what you are hearing, then maybe you need to be less invested in a hobby which all the pleasure comes from listening to music. -
Erik Tracy wrote: »So I contacted Chad at Epik - he was ok with me removing the amp from the back of the cabinet and have a look-see at the LFE jack.
Problem is, I removed all of the perimeter screws around the amp to try and remove the amp and the amp doesn't want to come off.
Has anyone here with an Epik sub removed the amp from the back of the cabinet? Is there some sort of adhesive used to hold it in place?
I was thinking of using a screw driver to pry it off the back.
Thanks,
Erik
adhesive or more likly a stubborn seal,try gently prying. -
I'd say check AVS or some other forum for advice before pulling/prying too hard, or get Epik CS to walk you through it on the phone.
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mdaudioguy wrote: »I'd say check AVS or some other forum for advice before pulling/prying too hard, or get Epik CS to walk you through it on the phone.
I got a hold of Chad at Epik - the plate amp has some acoustic sealer tape and it forms a really good seal to the cabinet - the trick is to use a zip tie thru the speaker terminal, make it into a loop to tug on and 'fffooomp' off comes the plate amp.
Problem now is there is nothing noticable as to why the LFE RCA jack is bad.
I'm hoping to just get a replacement amp and send the bad one back.
H9: If you don't trust what you are hearing, then maybe you need to be less invested in a hobby which all the pleasure comes from listening to music. -
Just as a follow up.
Chad will be sending me a replacement amp - no cost.
I should be back up and running soon with both LFE and Line Level inputs.
Thumbs up for good customer support from Epik!!:D
H9: If you don't trust what you are hearing, then maybe you need to be less invested in a hobby which all the pleasure comes from listening to music.
